Electrical door-alarm



(N0 Modl.

D. H. STREEPER.

ELECTRICAL DOOR ALARM.

No. 412,563. Patented Oct. 8, 1889.

WITNESSES:

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UNITED STATES PATENT OFFICE.

DANIEL H. STREEPER, OF NORRISTOXVN, PENNSYLVANIA.

ELECTRICAL DOOR-ALARM.

SPECIFICATION forming part of Letters Patent No. 412,563, dated October 8, 1889.

Application filed July 19, 1889.

To aZZ whom it may concern:

Be it known that I, DANIEL H. STREEPER, of Norristown, in the county of Montgomery and State of Pennsylvania, have invented a new and Improved Electrical Door-Alarm, of which the following is a specification, reference being had to the annexed drawings, forming a part thereof, in which- 'Figure 1 is a front elevation, partly in section, of a door-knob and lock to which my improvement has been applied; and Fig. 2 is a side elevation, partly in section.

Similar letters of reference indicate corresponding parts in both views.

The object of my invention is to provide a simple and effective alarm Which Will give notice Within when the door-knob is turned from the outside of the door.

My invention consists in the combination, With the knob-socket, of a switch-arm connected With the socket so as to turn with it,and

a contact-plate inserted in the door in the path of the switclrarm, the said knob socket and contact-plate being in the circuit of a battery including an alarm-bell, all as will be hereinafter more fully described.

To the door A is fitted a lock B, of ordinary construction, the said lock 13 being provided with two spindles axially in line with each other, and adapted to operate independently upon the mechanism of the lock in the usual way. To the knob-socket G, placed upon the outer spindle, is attached a switch-arm D, which'is covered by the collar E. In the face of the door is inserted a contact-plate F.

Serial No. 317,983. (No model.)

The lock B is connected with one pole of the battery G through the Wire a, and the hinges of the door, and the contact-plate F is connected through the Wire Z) and the doorhinges with the electric bellH, and the said bell is in turn connected with the remaining pole of the battery G. The electric bellHis provided with an electro-magnet c, which is capable of acting upon the armature (1, connected with the bell-hammer lever e.- So long as the door is opened by turning the inside knob the electric circuit remains unchanged; but when the outer knob is turned the snitch-arm D is brought into contact with the plate F and the circuit is closed, giving the alarm.

The bell represented as a part of my device is shown as a single-stroke bell; but it is obvious that I may employ a vibrating bell in lieu thereof whenever it may be necessary. 5 5

Having thus described my invention, I claim as new and desire to secure by Letters Patentr- The combination, with a door, its lock having operating-knob, and an escutcheon E, of the electric alarm and battery, the contactplate 13, secured to the door under the escutcheon and in the circuit of the battery, and the switch-arm D, secured to the knobshank and also concealed by the escutcheon, 65 substantially as set forth.

DANIEL H. STREEPER.

Vitnesses:

JOHN J OoRsoN, HAROLD CORSON. 

